1. Field of the Invention
The present invention relates to a vehicular lamp that uses a light-emitting element as a light source.
2. Prior Art
Recent years have seen adoption of many vehicular lamps having a light-emitting element serving as the light source.
Japanese Patent Application Laid-Open (Kokai) No. 2000-67610 discloses a vehicular lamp including a light-emitting element disposed to face forward on an optical axis extending in the longitudinal direction of the lamp and a translucent member disposed to cover the light-emitting element from its front side.
In this vehicular lamp, a central region of the translucent member which is located close to the optical axis is constructed so as to allow light from the light-emitting element, which has impinged on the translucent member, to emit forward from its front face. Further, the peripheral region of the translucent member which is located around the central region is constructed as a mortar-shaped light guiding body so as to emit light from the light-emitting element, which has impinged on the translucent member, forward from the surface of its leading end portion after repeated internal reflection on the rear and front faces of the translucent member.
The use of the translucent member in Japanese Patent Application Laid-Open (Kokai) No. 2000-67610 enables enhancement of the luminous flux utilization factor for the light from the light-emitting element but causes some problems.
One problem is that since the peripheral region of the translucent member is constructed as the mortar-shaped light guiding body, only the leading end portion of the peripheral region looks bright when the translucent member is observed from an area in front of the lamp. This causes another problem of unattractive appearance of the lamp in its lit-up state.
In addition, light from the light-emitting element which has impinged on the translucent member is randomly emitted forward from the surface of the leading end portion of the translucent member after having been internally reflected by the rear and front faces thereof in a repeated fashion. The further problem resulting from this fact is that light distribution control of the vehicular lamp with high precision cannot be made efficiently.